An unset or blank NEXT_PUBLIC_SHOPIFY_DOMAIN reached the Hydrogen client
as an empty storeDomain, which throws 'storeDomain is required and must
be non-empty'. Fall back to the tokenless mock.shop store, only send the
public token alongside a configured domain, and have the editor's Shopify
plugin read the same resolved config.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
